Conditions for the formation of defect‐induced bound exciton (DIBE) emissions in GaAs were investigated by molecular beam epitaxial method. Growth was made on both A‐ and B‐polarity substrates with (321), (221), and (211) orientations. For A‐polarity samples, (321)A and (211)A presented pronounced DIBE emissions. (221)A, however, exhibited no DIBE emission, instead it presented a dominant carbon donor‐carbon acceptor pair emission together with a small hump due to carbon donor‐related bound exciton emissions. For B‐polarity specimens, DIBE was completely vanished in all the three samples. It was theoretically demonstrated that DIBE is formed only when double‐handed Ga adatom site is existing.